A 2010 study found that the seas are acidifying ten times faster today than during the Paleocene-Exocene Thermal Maximum, when a mass extinction occurred. As Carl Zimmer reported, changes in ocean chemistry due to the burning of fossil fuels may portend a new wave of die-offs.READ THE e360 REPORT

that a steep rise in atmospheric levels of carbon dioxide has driven down pH levels in the oceans by 0.1 over the last century, to about 8.1, a rate 10 times faster than the closest historical comparison — a period of acidification 56 million years ago that triggered a massive ocean die-off. The oceans are vulnerable because they absorb excess carbon dioxide from the atmosphere, turning the water more acidic, which can inhibit organisms, such as oysters and coral reefs, from forming shells. “We know that life during past ocean acidification events was not wiped out — new species evolved to replace those that died off,” said Barbel Honisch, a paleoceanographer at Columbia University’s Lamont-Doherty Earth Observatory and lead author of the study, published in Science. “But if industrial carbon emissions continue at the current pace, we may lose organisms we care about — coral reefs, oysters, salmon.” Some scientists believe that oyster larvae die-offs along the west coast of the U.S. and Canada are related to increasingly acidic waters in that region.

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The Warriors of Qiugang, a Yale Environment 360 video, chronicles a Chinese village’s fight against a polluting chemical plant. It was nominated for a 2011 Academy Award for Best Documentary Short.
Watch the video.